Command which activates or creates a virtual environment. It's a modification of the original command which doesn't work for me properly.

use_env.sh

# The use_env call below is a reusable command to activate/create a new Python
# virtualenv, requiring only a single declarative line of code in your .env files.
# It only performs an action if the requested virtualenv is not the current one.
use_env() {
  typeset venv
  venv="$1"
  if [[ "${VIRTUAL_ENV##*/}" != "$venv" ]]; then
    if workon | grep -q "$venv"; then
      workon "$venv"
    else
      echo -n "Create virtualenv \"$venv\" now? (Y/n) "
      read answer
      if [[ "$answer" != "n" ]]; then
        mkvirtualenv "$venv"
      fi
    fi
  fi
}